The optimization of pomelo peel solid-state fermentation condition by Aspergillus aculeatus for naringinase

Abstract:

[Objective] The study aims to optimize solid-state fermentation conditions of citrus processing by-products with Aspergillus aculeatus for naringinase production. [Methods] The naringinase activity was detected by a high performance liquid chromatography method. The effects of solid water ratio, loaded sample, inoculation quantity and culture temperature were investigated on producing naringinase by single factor experiments and the fermentation conditions were further optimized with 3 factors at 3 levels in an orthogonal experimental design. [Results] Single factor experiments showed that solid water ratio, loaded sample and culture temperature had significant effects on the yield of naringinase, while inoculation quantity has no significant effect. The optimized fermentation conditions for A. aculeatus are: solid water ratio of 1:1 (W/V), loaded sample of 5 g/250 mL triangular flask, inoculation quantity of 1 mL at 30 °C for 8 days. Under optimal culture conditions, the activity of naringinase reached 8.19 IU/g dry substrate, which was 7.38-fold higher than that achieved before optimization. [Conclusion] There is significant improvement in naringinase production in pomelo peel solid-state fermentation by A. aculeatus after optimization. This study established a high-efficiency fermentation process for naringinase production.

Key words:Naringinase, Aspergillus aculeatus, Pomelo peel, Solid-state fermentation, Fermentation conditions